Absorption refrigerating machine



Dec. 12, 1967 J. M. HOLMAN ETAL 3,357,202

ABSORPTION REFRIGERATING MACHINE Filed Jan. 18, 1966 2 Sheets-Sheet 1 95 INVENTOR.

FIG. 2 JOHN L M. HOLMAN FIG. 3 JAMES 'M.'PORTER ROBERT P. NOVAK ATTORNEYS Dec. 12, 1967 J.- L. M. HOLMAN ET AL 3,357,202

ABSORPTION REFRIGERATING MACHINE 2 Sheets-Sheet Filed Jan. 18, 1966 MN m United States Patent 3,357,202 ABSORPTION REFRIGERATING MACHINE John L. M. Holman, Onalaska, James M. Porter, La

Crosse, and Robert P. Novak, Mindoro, Wis., assignors to The Trane Company, La Crosse, Wis., a corporation of Wisconsin Filed Jan. 18, 1966, Ser. No. 521,379 6 Claims. (Cl. 62-476) This invention relates to absorption refrigerating machines.

It is an object of the present invention to provide unitary refrigeration apparatus having an enclosure shaped to accommodate a generator, a condenser, an evaporator and an absorber with conservation of space and with the components shaped for efiicient operation.

It is another object of this invention to arrange in a sealed enclosure a generator pan bottom and a condenser pan bottom in substantially the same plane for ease of installation and to provide a space below said plane for receiving two evaporators of substantially the same size and shape.

It is another object of the invention to provide an elongated substantially cylindrical casing having an ovate cross-section, the major axis of which is substantially horizontal and offset downwardly and the minor axis of which is vertical, thereby providing a wide shallow area for the absorber.

It is another object of the invention to provide a compact efficient eliminator between the generator and the condenser to prevent the passage of drops of solution along with the refrigerant vapor flowing from the generator to the condenser.

It is another object of this invention to provide a two section evaporator to provide a larger area for flow of refrigerant vapor to the absorber and better distribution of the vapor to the absorber.

Other objects and advantages of this invention will be come apparent as the specification proceeds to describe the invention with reference to the accompanying drawings in which:

FIGURE 1 is a partly diagrammatic vertical sectional view of the apparatus of this invention taken on line 11 of FIGURE 4;

FIGURE 2 is an enlarged sectional view showing adjoining portions of the generator and condenser and the eliminator structure which prevents the flow of solution from the generator to the condenser;

FIGURE 3 is an enlarged sectional view taken on line 33 of FIGURE 2; V

FIGURE 4 is an enlarged longitudinal sectional View taken substantially on line 4-4 of FIGURE 1; and

FIGURE 5 is an enlarged partial sectional view taken on line 55 of FIGURE 4. I 7

Referring now to FIGURE 1 of -the drawing, the invention is embodied in an absorption refrigerating machine generally similar to that shown and described in US. Patent of E. M. Stubblefield et al. No. 2,986,906, dated June 23, 1958; and preferably employing a saline solution as an absorbent and a medium soluble therein such as water as a refrigerant.

A sealed shell 10 encloses the major components of the apparatus. A wall 12, U-shaped in cross-section and tubes 14 form a generator 11. A heating medium in liquid or gaseous form is circulated from a suitable source through the tubes 14 to boil refrigerant from the absorbent solution.

A condenser 15 has a wall 16 extending from wall 12 of shell 10 to provide a space for tubes 17 of condenser 15.

Wall 12 of generator 11 and wall 16 of condenser 15 divide the interior of shell 10 into a high pressure cham- 3357,22 Patented Dec. 12, I967 her containing the generator 11 and the condenser 15 and into a low pressure chamber containing evaporator 18, evaporator 19 and absorber 20.

Evaporators 18 and 19 have respectively pans 22 and 24 for collecting refrigerant liquid. Evaporator 18 has a plurality of tubes 26 and evaporator 19 has a plurality of tubes 28. A heat transfer fluid to be cooled is circulated by a pump (not shown) through a conduit 30 to the tubes 26 of evaporator 18 and thence through tubes 28 of evaporator 19 from which it flows through conduit 32 to a refrigeration load such as an air conditioning system. The flow of the heat transfer fluid through the evaporators may be in parallel instead of in series as described above.

Refrigerant liquid from condenser 15 flows to evaporator 18 through a suitable pressure reducing device such as the orifice 34. A pan 36 joins the evaporator pans 22 and 24 to provide a passageway for the flow of refrigerant liquid from evaporator 18 to evaporator 19 and from evaporator 19 to a refrigerant liquid sump 38. Refrigerant liquid flows from sump 38 through conduit 40 to a float switch 42 which opens when the level drops below a predetermined point. A screen 44 in sump 38 prevents foreign particles from passing from sump 38 to conduit 48. During normal operation a level of liquid is maintained in the evaporators whereby refrigerant is stored therein.

Refrigerant liquid flows from float switch 42 through conduit 46 to a pump 48 driven by a motor 49. Pump 48 delivers refrigerant liquid through conduit 50 to a spray tree 52 in evaporator 18 and a spray tree 54 in evaporator 19. Float switch 42'opens the electrical circuit to motor 49 when the level of refrigerant drops below a predetermined level.

Eliminators 56 are mounted on each side of the evaporators 18 and 19 to separate droplets of liquid refrigerant from the refrigerant vapor stream flowing from the evaporators 26 and 28 to the absorber 29 through passageways 58, 60, and 62. The droplets of refrigerant liquid removed by the eliminators 56 descend to the evaporator pans 22 and 24. Eliminators 56 comprise a plurality of spaced vertically extending plates which have a V-shaped cross-section.

An overflow pipe 64 in the conduit 36 conducts refrigerant liquid from conduit 36 to the absorber 20 when the refrigerant level in the conduit exceeds a predetermined level due to abnormal operation. The level in conduit 36 is substantially the same as the level in the evaporators 18 and 19 because it is in open communication with the evaporators.

A pump 66 driven by a motor 68 receives absorbent solution from the absorber through conduit 70 and delivers solution through conduit 71 to heat exchanger 72 from which it flows through conduit 73 to generator 11 where it is concentrated.

The concentrated solution flows from generator 11 through conduit 74 to heat exchanger 72 from which it flows through conduit 76 and mixes with dilute solution flowing from theabsorber through conduit 78. The mix ture flows through conduit '79 to pump 80 driven by a motor 81. Pump 80 delivers the solution through a conduit 82 to an absorber spray tree 83 which sprays the solution over the tubes 84 in the absorber 20.

Cooling fluid from a suitable source 86 is conducted .through the tubes 84 of the absorber from which it flows through conduit 87 and thence through the tubes 17 of the condenser 15. From the condenser the cooling fluid flows through conduit 88 to the source which can be a cooling tower in which the fluid is evaporatively cooled by air.

The structure for preventing solution from being carried from the generator to the condenser along with the refrigerant vapor will now be described. Referring to FIGURES 1 and 2, there is a baffle 90 secured to wall 12 of the generator 11. A trough-shaped baffie 91 is secured to the shell 10. The bafiies 90 and 91 cooperate to require the vapor to change direction through an angle of substantially 180. This change of direction causes the liquid droplets to strike the surfaces of the bafiies and the shell and run down the surfaces thereof. There are several pipes 92 spaced along the length of the shell 10 extending downwardly from trough 91 to drain liquid from trough 91 to the bottom portion of baifie 90.

An eliminator 94' has vanes 95 which intercept droplets of solution. Solution from bafile 91 flows through holes 93 and downwardly through pipes 92. Solution from eliminator 94 flows through a perforated plate strainer 96 to the bottom baffle 90.

There are several pipes 97 spaced along the length of the baflie 90. Solution from baffle 91 flows into pipe 97 through holes 98 and flows downwardly into the lower portion of the generator 11.

The perforated plate strainer 96 provides a quiet zone at the bottom of the baffle 90 for the flow and collection of solution without disturbance from the flow of refrigerant vapor.

It has been found that the absorbent solution becomes substantially diluted after passing downwardly over relatively few rows of tubes of the absorber. As the absorbent solution becomes diluted it is less effective in absorbing refrigerant vapor. Therefore, it is important to provide an absorber tube bundle having a transverse horizontal dimension several times greater than the vertical dimension. In order to accomplish this without increasing the shell size beyond economical limits, the shell is made ovate in cross-section with the ratio of the maximum horizontal dimension to the maximum vertical dimension greater than 5 to 4. It is desirable that the maximum horizontal dimension shall be located from the bottom of the shell approximately one-third of the vertical dimen sion of the shell.

Although preferred embodiments of our invention have been shown and described, it is contemplated that many changes may be made without departing from the scope or spirit of our invention and we desire to be limited only by the claims.

We claim:

1. An absorption refrigerating machine comprising a first chamber operating at high pressure, a generator in said first chamber, a condenser in said first chamber, said condenser being in fluid fiow communication with said generator to condense refrigerant vapor from said generator, a second chamber operating at a low pressure, an absorber in the lower portion of said second chamber, two evaporators in said second chamber and arranged above said absorber, said evaporators being spaced from each other to provide a first downwardly extending passageway between said evaporators for the flow of refrigerant vapor downwardly from said evaporators to said absorber, said evaporators being spaced from the walls of said second chamber to provide separate additional passageways between said evaporators and said absorber for the flow of refrigerant vapor from said evaporat'ors to said absorber, means for circulating anabsorbent solution from said absorber to said generator and from said generator to saidabsorber and means for conducting refrigerant liquid from said condenser to said evaporators.

2. An absorption refrigerating machine according to claim 1 in which the means to conduct refrigerant liquid to said evaporators includes a conduit for conducting refrigerant liquid from said condenser to one of said evaporators and means for conducting refrigerant liquid from said one. of said evaporators to other of said evaporators.

3. An absorbption refrigerating machine according to claim 1 in which the means for conducting refrigerant liquid from said condenser to said evaporators includes a conduit for conducting refrigerant liquid to one of said evaporators and a conduit extending across the aforementioned first downwardly extending passageway to conduct refrigerant from said one of said evaporators to the other of said evaporators.

4. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container of ovate cross-section in which the ratio of the maximum horizontal dimension to the maximum vertical dimensions is greater than 5 to 4 and in which the maximum horizontal dimension of the cross-section of the container is located below the horizontal centerline of the cross-section of the container, a partition dividing the interior of the container into an upper high pressure chamber and a lower low pressure chamber, a generator in said upper high pressure chamber, a condenser in said upper high pressure chamber to receive and condense refrigerant vapor from said generator, an absorber in the bottom of said low pressure chamber, two evaporators in said low pressure chamber and arranged above said absorber, said evaporators being spaced from each other to provide a first downwardly extending passageway between said evaporators for the flow of refrigerant vapor downwardly from said evaporators to said absorber, said evaporators being spaced from the walls of the low pressure chamber to provide separate additional passageways between said evaporators and said absorber for the fiow of refrigerant vapor from said evaporators to said absorber, means for circulating an absorbent solution from said absorber to said generator and from said generator to said absorber and means for conducting refrigerant liquid from said condenser to said evaporator.

5. An absorption refrigerating machine according to claim 4 in which the cross-section of the container is such that the maximum horizontal dimension of the cross-section of the container is located from the bottom of the container a distance approximately equal to one-third of the maximum vertical dimension of the cross-section of the container.

6. An absorption refrigerating machine comprising a unitary sealed horizontal substantially cylindrical elongated container, a substantially flat horizontal partition dividing the container into an upper high pressure chamber and a lower low pressure chamber, a generator and a condenser in said high pressure chamber, a partition extending upwardly from said substantially flat horizontal partition and partially separating said generator space from said condenser space, two baffles arranged in a space between sa-id partition and the top of said container, said baffies each having sides angularly arranged with respect to each other, said baffles being spaced from each other to provide an elbow passageway for conducting refrigerant vapor from said generator to said condenser, a liquid eliminator in said elbow passageway at its downstream end for removing droplets of absorption solution from the refrigerant vapor stream, means for returning said droplets of solution from said elbow passageway to the generator, an evaporator in said lower low pressure chamber, an absorber in said lower low pressure chamber, means for circulating an absorbent solution from said absorber to said generator and from said generator to said absorber and means for conducting liquid refrigerant from said condenser to said evaporator.

References Cited UNITED STATES PATENTS LLOYD-L. KING, Primary Examiner. 

1. AN ABSORPTION REFRIGERATING MACHINE COMPRISING A FIRST CHAMBER OPERATING AT HIGH PRESSURE, A GENERATOR IN SAID FIRST CHAMBER, A CONDENSER IN SAID FIRST CHAMBER, SAID CONDENSER BEING IN FLUID FLOW COMMUNICATION WITH SAID GENERATOR TO CONDENSE REFRIGERANT VAPOR FROM SAID GENERATOR, A SECOND CHAMBER OPERATING AT A LOW PRESSURE, AN ABSORBER IN THE LOWER PORTION OF SAID SECOND CHAMBER, TWO EVAPORATORS IN SAID SECOND CHAMBER AND ARRANGED ABOVE SAID ABSORBER, SAID EVAPORATORS BEING SPACED FROM EACH OTHER TO PROVIDE A FIRST DOWNWARDLY EXTENDING PASSAGEWAY BETWEEN SAID EVAPORATORS FOR THE FLOW OF REFRIGERANT VAPOR DOWNWARDLY FROM SAID EVAPORATORS TO SAID ABSORBER, SAID EVAPORATORS BEING SPACED FROM THE WALLS OF SAID SECOND CHAMBER TO PROVIDE SEPARATE ADDITIONAL PASSAGEWAYS BETWEEN SAID EVAPORATORS AND SAID ABSORBER FOR THE FLOW OF REFRIGERANT VAPOR FROM SAID EVAPORATORS TO SAID ABSORBER, MEANS FOR CIRCULATING AN ABSORBENT SOLUTION FROM SAID ABSORBER TO SAID GENERATOR AND FROM SAID GENERATOR TO SAID ABSORBER AND MEANS FOR CONDUCTING REFRIGERANT LIQUID FROM SAID CONDENSER TO SAID EVAPORATORS. 